Tubular lamp base



M y 30, 9- I c. s. PETERSON 2,

TUBULAR LAMP BASE Filed March 17, 1938 Fig. l.

Inventor: Conrad 8. Peterson,

b ZM

His AttOTfieg.

Patented May 30, 1939 2,160,786 TUBULAR LAMP msr.

Conrad s. Peterson, Cleveland Heights, hio,aasigner to General Electric Company, a corporation of New York Application March 17, 1.938, Serlal'No. 196,458

(Cl. 17l 126) Claims.

My invention relates to electric lamps and sim-- ilar devices, and more particularly to a base and socket construction for such devices. Still more particularly, my invention relates to a base and socket construction for electric lamps of the double-ended discharge type, in which a filamentary electrode is mounted at each end of the lamp. In electric discharge lamps of the tubular l0 double-ended type, it is necessary that each end of the lamp be provided with a suitable base to thereby properly mount the lamp. However, it is "frequently desirable to mount a number of such lamps in axial alignment with each other so as to produce an extended line of light. To obtain the nearest. approach to an uninterrupted line of light, it is essential that the longitudinal extent of the unilluminated portions at each end of the lamp, occasioned by the necessary base 9 and socket construction thereat, be maintained at a minimum. Accordingly, one object of my invention is to provide a suitable base and socket construction for electric lamps of the tubular type which will be of minimum extent longitudinally of such lamp.- 1

Another object of my invention is to provide a base and socket construction for electric lamps of the tubular double-ended type whereby the lamp may be readily inserted in its socket and. 3 securely locked therein so as to effectively prevent unwarranted or premature disengagement therefrom.

Still another object of my invention is to pro- I vide a suitable base and socket. construction for double-ended lampshaving a pair of current carrying leads at each end of the lamp whereby the said leads may be both connected in the proper manner in the lamp circuit.

, A further object of my invention is to provide a base and socket construction for doubleended lamps in which the current-conveying members thereof are entirely concealed and unexposed when the base is assembled in its socket so as to prevent short-circuits as well as injurious 5 shocks therefrom.-

Astill further object'of' my invention is to provide a lamp base having a removable insert therein whereby the connection of the lamp filament or electrode leads to the contact members so oi the base may be accomplished in a convenient and simple manner.

Further objects and advantages of my invention will appear-from the following description of a species thereof and from the accompany- 5 ing drawing.

In the drawing, Fig. 1 is a side view, partly in section, of -a tubular lamp base and socket construction comprising my invention, the bases being mounted on a lamp disposed in correct position preparatory to its insertion in the socket; Fig. 2 is an isometric view of one of the bases and sockets shown in Fig. 1 with the base insert removed and the socket partly broken away; Fig. 3 is a view of the inner end of one of the bases shown in Fig. 1; Fig. 4 is a sectional view on the line 4-4 of Fig. 1; and Fig. 5 is an enlarged fragmentary view of a modified form of lamp base according to my invention.

Referring to the drawing, the base and socket construction there illustrated is shown mounted on and arranged to receive an electric lamp III of the tubular double-ended discharge type having a filamentary electrode II at each end, each electrode being coated with an electron-emissive material. Each electrode is provided with a pair of leads l2, I! through which current is passed to preheat the electrode.

The base ll according to my invention com-' prises a molded cup-shaped body or shell l5 of suitable insulating material, preferably Bakelite, and consists of a bottom or end wall 16 and a cylindrical wall ll. The said cylindrical wall is of the proper internal diameter to fit loosely over the end or neck portion I! of the lamp envelope [9, to which portion the base is united by suitable cement 20. formed with an integral socket-engaging tab 2| extending from the cylindrical wall ll of said body. The tab 2| is made of the same material as the body It, being molded therewith, and consists of a disc-shaped portion 22 connected to the body l5 of the base by a relatively narrow neck portion 23. Molded to the inner surface 24 of the base end wall I and extendi'ngthrough and outwardlybeyond the cylindrical wall ll, 4

are a'pair of contact strips 25, 26, preferably of brass. The outwardly extending portions of the strips 25, 26 are curved so as to provide arcuate portions 21 conforming to and molded to the edges 28 of the tab 2|. The outer ends of the arcuate portions '21 terminate short of each other, being separated by a spacing lug, 29 on the tab 2|. If desired,. the said outer ends of the .arcuate portions-21 may be bent inwardly, as shown at 21' in Fig. 5, whereby the spacing lug 29 definitely prevents separation of the arcuate portions 21 from the edge 28 of the-tab. Where the base H is one for use with a lamp of a relatively large diameter, the cylindrical wall I1 is provided with an outwardly extending :0 The base body I5 is.

positioning lug or ear 30 suitably shaped to engage a co-operati-ng surface on the lamp socket to thereby properly space the lamp from its fixture.

To permit easy attachment of the electrode leads I2, I 3 to the base contact strips 25, 26, the end wall l5 of the base is provided with a centrally located and circular removable insert 3|. The base I4 is first cemented in place on the end of the lamp with the said insert 3| removed. The opening 32 in the base and wall l6 thus provides ready access to the interior of the base and exposes the two contact strips 25; 25 extending across the inner surface of the end wall. The two electrode leads l2, l3 can thus be very easily soldered or welded to the two contact strips 25, 26respectively, as shown in Fig. 2. The insert 3| is then replaced in the opening 32 in the base end wall Hi. If desired, the insert may be colored to thereby indicate the color of the light emitted by the lamp during operation. This feature is particularly advantageous in the case of fluorescent discharge lamps in which the fluorescent material coated on the glass envelope may be of a different color from the actual color of the light emitted during operation of the lamp.

The socket 33 for co-operationwith the above-- described base |4 comprises a hollow body 34 of insulating material, preferably Bakelite, a pair of spring contact members 35 mounted therein, and a rear cover plate 35 riveted to the body portion 34. The said body portion is formed with a forwardly extending hollow projection 31 the front surface 38 of which is curved to conform to the curvature either of the cylindrical wall ll of the lamp base l0 (in the case of the smaller diameter lamps) or to the curvature of the ear 39 on the lamp base (in the case of the larger diameter lamps). An opening or slot 39 in the body portion 34 extending through the projection 31 is adapted to receive the tab 2| of the lamp base Ill.

The contact members 35 are preferably made of phosphor bronze and are held in place against a positioning shoulder 40 in the socket by the rear cover plate. 36. As shown in Fig. 2, the rear surface of the socket body portion 34 is provided with grooves or channels 4| adapted to snugly receive the contact members 35 and so further position and support the same. To still further assist in positioning and supporting the contact members 35 in the socket, each of said members is provided with two forwardly extending lugs 42 and 43 (Figs. 1 and 2) spaced apart the proper distance to snugly receive a positioning lug 44 in the socket body portion 34. Each contact member 35 is also provided with a spring finger 45 disposed in the slot 39 in the body portion 34 and extending forwardly into the projection 31. The forward extremities of the spring fingers 45 are curved oppositely away from each other so as to form arcuate endportions 46 which are adapted to spring over and engage the arcuate portions 21 of the base tab 2| upon insertion thereof in the socket.

As shown in Fig. 1, the two sockets 3|, 3| are preferably mounted on a suitable fixture 41, being spaced apart the proper distance to freely receive the base tabs 2| in the slots 39. The socket contact members 35 are connected to the circuit by leads 48, 43 which may be either soldered directly to the lugs 43 or attached thereto by screws 49 threaded into said lugs.

To insert thelamp III in the sockets 33, 33, the lamp is simply placed in the position shown in Fig. '1, with the base tabs 2| opposite the socket slots 39, and then moved toward said sockets so that the tabs 2| enter said slots. The insertion of the tabs 2| spreads the spring fingers 45 apart until the arcuate portions 46 thereof snap over 'the corresponding arcuate ends 21- of the base contact strips 25, 26 to thereby securely lock the base tabs in the sockets. The engagement of the arcuate portions 45 of the spring contact fingers 45 with the arcuate ends 21 of the base contact strips 25, 2' accordingly connects the latter to the lamp circuit and at the same time provides a. positive lock against unwarranted or premature disengagement of the lamp from the socket.

What I claim as new and desire to secure by' Letters Patent of the United States is:

1. A base for electric lamps and similar devices comprising a cup-shaped member of insulating material having an end wall, a cylindrical wall, and a disc-shaped tab extending outwardly from said cylindrical wall, and a pair of spaced contact strips secured to said member and extending across the inner surface of said end wall, said contact strips further extending throughv said cylindrical wall and being curved to conform to and engage the edge of said tab.

2. A base for electric lamps and similar devices comprising a cup-shaped member of insulating material having an end wall and a cylindrical wall, said .end wall being provided with a removable insert, and a pair of spaced contact strips secured to said member and extending across the removable insert in said end wall and through said cylindrical wall.

3. A base for electric lamps and similar devices comprising a cup-shaped member of insulating material having an end wall and a cylindrical wall, said end wall being provided with a centrally located circular insert removable therecomprising a cup-shaped member of insulating material having an end wall, a cylindrical wall, and a disc-shaped tab extending outwardly from said cylindrical wall, said end wall being provided with a removable insert, and a pair of spaced contact strips secured to said member and extending across the removable insert in said end wall, said contact strips further extending through said cylindrical wall and being curved to conform to and engage the edge of said tab.

5. An electric lamp or similar device comprising a tubular envelope, a filament sealed within said envelope at each end thereof and having a pair of leads extending through said envelope, a base mounted on each end of said envelope, each of said bases comprising a cup-shaped member of insulating materialhaving an end wall provided with a removable insert, a cylindrical wall, a disc-shaped tab extending outwardly from said cylindrical wall, and a pair of spaced contact strips secured to said member and having portions extending across the removable insert in said end wall, the pair of lead wires adjacent each base being connected to said portions of the contact strips,'said contact strips further extend- CONRAD S. PETER/SON. 

